if by cache you mean that your entire system is on your drive and that the hdd is for backups or games that you’re not currently playing but don’t want to reinstall, yes.

it’s not secure by design, since it’s not made to be secure, and also uses unstable versions of a lot of packages to make certain exploits work

afaik they don’t puke half digested food in each others mouths to make sure they all get to eat, so no.

sry, nvm, I confused boric acid and borax, which kills insects by solidifying inside their bodies.

This doesn’t really work with roaches. it works really well with ants, since they drink it, feed it to their larvae, sisters and queen, who then all die. (if you dissolve it in water)

yes

android is very sandboxed, so anything you do in termux/userland can’t affect the android on your phone (unless you’re rooted)